Planting unit

ABSTRACT

A planting unit utilizing a single disk opener supported for rotation about a horizontal axis offset at a small angle from the transverse direction for opening a furrow. A seed tube assembly is located adjacent the rearward facing side of the disk and includes a runner extending forwardly of the lower portion of the seed tube for holding loose soil out of the furrow in advance of seed or other material deposited therein, the runner being located in the shadow of the disk so as not to significantly contact or disturb the side of the furrow. The opener is mounted on an arm which is pivotable about a relatively low point so as to be oriented at a relatively flat angle with respect to the ground and to maintain the general orientation of the opener as it moves through the soil throughout the range of pivotal movement of the arm. The planting unit can include one or more pivotable press wheels which can be mounted for pivotal movement about the same axis as a pivotable gauge wheel adjusting arm. The press wheels preferably include a relatively narrow first press wheel which travels in the bottom of the furrow for firmly pressing seed or other material into the bottom of the furrow, and a second press wheel having a double beveled edge that can be adjustably positioned and oriented for precise placement of soil into covering relation to the seed or other material.

This is a continuation-in-part of application Ser. No. 08/384,660, filedFeb. 6, 1995, now U.S. Pat. No. 5,595,130.

BACKGROUND OF THE INVENTION

The present invention relates generally to planting units for forming atrench or furrow in the ground and depositing seed therein, and moreparticularly, to a single disk planting unit adapted for opening arelatively narrow furrow in the soil and precisely placing seeds, grainsor other materials in the furrow, which unit is adapted to be used inclosely spaced side by side relation with other planting units, andwhich unit is adapted for use in a wide range of tillage conditionsincluding conventional till, minimum till, and some no tillapplications, as well as in wet soils and other troublesomeapplications.

Tilled soil conditions generally fall along a continuum that can beloosely divided into three categories. At one end of the continuum isthe above-mentioned category known as conventional till which generallyincludes tillage conditions wherein the soil is worked into agarden-like condition before planting. Conventional till is loose andcrumbly and has little intact plant residue, sometimes called "trash",present on the surface. A middle category is minimum till wherein thesoil is only lightly tilled prior to planting. In minimum till, the soilis firmer and some intact plant residue is present when the next crop isplanted. The third category, located at the opposite end of thecontinuum from conventional till, is no till, wherein the soil remainslargely undisturbed after harvest, and the next crop is planted amongstanding weeds, remaining plant root structure, and other trash. Of thethree general categories, conventional till is the oldest and mostwidely used. However, minimum till and no till, often together calledconservation till, are becoming increasingly popular.

An important problem encountered when planting in conventional andminimum till is the frequent presence of several inches of loose soil onthe surface of the ground which can fall into a furrow formed by aplanting unit in advance of seeds, grains or other material beingdeposited therein so as to result in non-uniform placement of thematerial in the furrow. Also, many known planters, drills and openerunits tend to plow or push this loose top soil to the side, such thatthe displaced soil interferes with the operation of adjacent units. Thisis particularly problematic where adjacent units are positioned in astaggered fore/aft arrangement as the forward units can actually pushsoil into the path of the aft units making their operation moredifficult and the aft units can push soil over the seed or othermaterial planted by the forward units such that as a result that seed ormaterial is planted too deep.

Conservation till provides advantages over conventional and minimum tillincluding less chemical loss and redistribution, less erosion, and otherbenefits, but because the soil has been worked less, it is moredifficult to penetrate to plant in and known implements for planting inconservation till typically utilize relatively high down pressure topenetrate the surface of the soil and form a relatively wide furrow.This requires a heavier implement which is more costly, and pulling theheavier conservation implements, particularly through firm soil, rootsand trash, requires relatively large horsepower tractors which arethemselves heavy and are known to cause soil compaction problems. Thelarger tractors are also costly. Additionally, the known conservationtill planting units are all relatively wide and thus do not facilitateplacement in closely spaced relation, particularly closely spaced sideby side relation, because trash has been found to become easily lodgedbetween the units and collect there so as to disrupt the function andeffectiveness of the units, instead of flowing between the units. Thismaterial flow problem is also present when the units are staggered asexplained above. Staggered conservation units likewise can cause thesame soil displacement problems discussed above.

Some soil types have been also found to be problematic for known openerunits, such as river bottom soils including heavy, silty components,known as "gumbo" soils, found in areas such as the Mississippi rivervalley region of southern Illinois and elsewhere. One reason for thishas been the observation that these soils tend to fracture and fragmenteasily, thus making it difficult to open the soil without breaking itup. Other problem soils include sandy loams which can be extremely fineand almost fluid-like making it difficult to form a narrow, controlledfurrow and deposit seed in the bottom of the furrow before it is coveredwith soil. Also, known opener units can become mired in the soil if itis too wet, resulting in delays that can reduce crop yields.

On attempted solution for overcoming the above discussed shortcomings ofstaggered forward and aft opener units is to set the forward units toplant at a shallower depth than the aft units. However, this does notwork in all cases, and in some cases the front openers may have to belocked in an up, non-planting position, which is less productive and forobvious reasons is inconvenient. Another problem with staggered units isthat if the staggered units are to be mounted on a single tool bar, theforward and aft units will require different mounting hardware, thusincreasing their cost.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide animproved planting unit for conventional till and other applicationswhich forms only a very narrow furrow or trench in the soil and therebydisrupts less soil for better moisture and nutrient preservation, lesschemical loss and redistribution, and less erosion when planting.Another object is to provide a planting unit that can be used in wetsoils. It is yet another object to provide a planting unit forconventional till which requires less horsepower for pulling and can beused at faster operating speeds. Still another object is to provide aplanting unit for conventional till which has at least some utility inconservation till.

It is another object of the present invention to provide an improvedplanting unit that enables a drill to plant in relatively narrow rowswithout using staggered opener assemblies. Another object is to providea planting unit which forms a relatively narrow furrow and holds loosesoil out of the furrow long enough to enable seed or other material tosettle in the bottom of the furrow. Another object is to provide aplanting unit that more precisely places seed or other material in thefurrow.

Another object is to provide a planting unit that is easy to adjust forplanting depth and down pressure. Another object is to provide aplanting unit having down pressure that only minimally affects plantingdepth in softer soils.

Another object of the present invention is to provide an improvedplanting unit for conventional till and other applications whichprovides better planting characteristics more economically than at leastmost prior art planting units, and which is also easier to lubricate andservice.

These and other objects and advantages of the present invention willbecome apparent after considering the following description of theinvention in conjunction with the accompanying drawings.

SUMMARY OF THE INVENTION

In accordance with the above objects, the present invention overcomesmany of the shortcomings and limitations associated with using knownplanting unit constructions and teaches the construction and operationof several embodiments of a planting unit which opens a narrow furrow orslit in the soil, and precisely deposits seed, fertilizer, or othermatter in the furrow with only minimally disturbing the soil. Thepresent unit can be of relatively lightweight construction and requiressubstantially less horsepower to pull through conventional till andconservation till compared to known planting units. The present plantingunit is also relatively narrow, enabling forming closely spaced rowswithout requiring a staggered arrangement.

The present planting unit construction includes an improved openerassembly utilizing a single at least generally flat disk blade supportedin a substantially vertical attitude for rotation about an axis which isslightly angled with respect to the transverse direction, that is, thedirection transverse to the forward direction of travel of the unit, atabout 5°, although somewhat larger or smaller angles could be used, theangle selected depending on the application. The opener further includesan adjustable gauge wheel to enable setting different disk penetrationdepths, and a seed tube assembly including a boot or runner member. Inseveral preferred embodiments of the invention, the gauge wheel providesthe capability that regardless of the gauge wheel adjustment, the bottomportion of the gauge wheel is always located in close proximity to theregion where the disk edge exits the ground, which helps maintain theintegrity of the adjacent side of the furrow and is important as will beexplained. The seed tube boot or runner is located in the furrowadjacent the opposite side in position to prevent loose soil fromfalling into the furrow long enough to enable seed to be deposited inthe bottom region of the furrow, but does not act to significantly firmor form the furrow. The seed tube boot or runner is designed for lessdrag, and preferably further includes means for better preventingclogging of the seed tube outlet.

The opener is supported utilizing a pivotable arm assembly, onepreferred assembly including a lower arm member which is pivotallyattached to an upper arm member. The upper arm attaches to the rockshaft, tool bar or cross beam on the implement frame and extendsdownwardly and rearwardly therefrom terminating at the pivot point forthe lower arm member. Importantly, the pivot point of this preferredassembly is substantially lower compared to known units, which resultsin the lower arm member being oriented at a much flatter angle. This isan important advantage of this assembly because it enables a greaterdegree of pivotal movement of the lower arm member without substantiallychanging the relationship of the opener with respect to the soil,thereby limiting adverse effects on planting depth and seed tube outletclogging. According to another preferred embodiment, the lower armmember carries a bearing assembly at least largely internally forrotatably supporting the disk, which internal bearing assembly enablesthe unit to have an overall narrower width so that units can be moreclosely spaced together. According to an alternative preferredembodiment, the disk bearing is carried on a member located in a cavityof the gauge wheel, which is also a more compact assembly widthwise.Other opener improvements include a gauge wheel that facilitates theflow of soil and trash between adjacent units and a seed tube boot orrunner that does a better job cleaning the surface of the disk and whichbetter prevents the build up of trash between the disk and the openerframe.

The present planting unit further preferably includes furrow closingmeans located in trailing relation to the opener assembly, which closingmeans include a narrow first press wheel capable of following along thebottom of the seed furrow and pressing the seed firmly into the bottomof the furrow, and a rearwardly positioned second press wheel or closingwheel of relatively lightweight construction including a speciallydouble beveled edge portion for placing soil over the deposited seed.Other improvements include optional spring means associated with therespective press wheels which can be adjusted more quickly and easilythan known constructions, and which require no tools for adjustment. Therear press wheel angle and position are also adjustable for fine tuningsoil coverage. In several embodiments, the two press wheels arepivotably mounted in coaxial relation with the mounting means for thegauge wheel for improved and easier lubrication and servicing.Additionally, the present invention can include adjusting means for thegauge wheel which provide more precise adjustment and planting depth.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a planting unit according thepresent invention mounted on the rockshaft of a typical prior artplanting implement, which unit is a right hand unit, and is shown in thefield position in engagement with the ground;

FIG. 2 is an enlarged fragmentary side elevational view of the openerarm assembly of the unit of FIG. 1;

FIG. 3 is an enlarged perspective view of the upper spring bracketmembers of the opener arm assembly shown in FIG. 2;

FIG. 4 is an enlarged rear view of the bracket members of FIG. 2 showingan upper spring retainer and a spacer member of the opener arm assemblyin association therewith;

FIG. 5 is an enlarged perspective view of a lower spacer assembly whichforms a part of the opener arm assembly of FIG. 2;

FIG. 6 is a top view of a planting unit according to the presentinvention, which unit is the same as the unit of FIG. 1 except that itis a left hand unit, showing the orientation of the various wheelmembers and the curved shape of the lower arm member of the unit;

FIG. 7 is a right side elevational view of the planting unit of FIG. 6,showing the various wheel members and the lower arm member of the unitin phantom lines;

FIG. 8 is an enlarged perspective view of the mounting plate assembly ofthe unit of FIG. 6 showing the press wheel mounting arms and relatedspring members in position thereon;

FIG. 9 is a partial sectional view of the planting unit of FIG. 1 takenalong lines 9--9;

FIG. 10 is an enlarged side elevational view of the seed tube assemblyof the unit of FIG. 6, showing the disk member of the unit in phantomlines;

FIG. 11 is a rear view of the seed tube assembly of FIG. 6;

FIG. 12 is an enlarged rear view of the second press wheel andassociated arm member of the unit of FIG. 1;

FIG. 13 is an end view of the press wheel shown in FIG. 12;

FIG. 14 is an enlarged fragmentary side elevational view of a secondembodiment of a planting unit according to the present inventionincluding the gauge wheel and press wheel assemblies mounted on a singlepivotal axis;

FIG. 15 is a top view of the planting unit of FIG. 14;

FIG. 16 is a fragmentary cross-sectional view taken along lines 16--16of FIG. 15;

FIG. 17 is a side elevation view of a third embodiment of a plantingunit according to the present invention;

FIG. 18 is a fragmentary partial cross-sectional view of the plantingunit of FIG. 17;

FIG. 19 is a top view showing a plurality of the planting units of FIG.17;

FIG. 20 is a side view of still another embodiment of a planting unitaccording to the present invention;

FIG. 21 is a top view of the planting unit of FIG. 20;

FIG. 22 is a fragmentary, partial cross-sectional view of the plantingunit of FIG. 20;

FIG. 23 is an enlarged side view of the seed tube assembly of the unitof FIG. 20, showing the disk 50 in phantom;

FIG. 24 is an exploded view of gauge wheel 52 showing the installationof an optional hub cap thereon; and

FIG. 25 shows gauge wheel 52 with the hub cap installed thereon.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1, there is shown a planting implement 10 having amain frame 12 supported for forward movement in the direction indicatedby the arrow A by wheels 14. The planting implement 10 includes aforward hitch 16 adapted for connection to a towing vehicle such as atractor. A hopper or seed box 18 is mounted on main frame 12 and isadapted for receiving and discharging material such as seed, grain orfertilizer to metering means 20 and then to hoses 22 through which theseed or other material can flow to opener assemblies 24 constructedaccording to the present invention. The opener assemblies 24 are mountedin side by side relation on a rockshaft 26 rotatably mounted on frame12. The implement 10 can include any number of opener assemblies 24corresponding to the width of the implement, and the opener assembliesshould include an equal number of right hand units (shown) and left handunits (e.g., FIG. 6) so as to equalize side draft forces acting on theimplement. Further, although a planting implement 10 is shown, theopener assemblies 24 may be used with other implements, such as an airseeder in which case the assemblies 24 may be mounted at a number oflocations on the seeder frame 12. The opener assemblies 24 form narrowfurrows of uniform depth in the soil and precisely deposit the meteredseed or material discharged from the hopper 18 into the furrows, as willbe explained.

The opener assemblies 24 are each mounted for pivotal movement relativeto rockshaft 26 on an opener arm or draw bar assembly 28 which alsoforms part of the invention. The opener arm or draw bar assembly 28includes an elongated upper arm member 30 having a first end portion 32which is fixedly attached to rockshaft 26 using U-bolts 34 secured intoposition with nuts 60 (FIG. 2), and an opposite second end portion 36which is generally located rearwardly and below first end 32 dependingon the orientation of the rockshaft, as will be explained. A lower armor draw bar 38 on which the opener assembly 24 is mounted has a forwardend portion 40 pivotally attached to lower end portion 38 of upper arm30 by flange bolt 42. Although any suitable pivotal attachment meanscould be used here, the pivotal attachment means shown include a hollowpin (not shown) with the end outside diameters tapered and splitbushings (not shown) with matching tapers. When the flange bolt 42 istightened through the bushings and the hollow pin, it causes thebushings to expand as they slide on the hollow pin. The bushings and pinbecome tight in the upper arm 30 and minimize the looseness of the lowerarm 38 thus maintaining more accurate positioning of the angled diskblade 50 under side loading. In operation, with opener assembly 24 inits field position engaged with the soil 44 as shown, lower arm 38 willbe oriented at an acute angle with respect to horizontal of from about0° to about 20°, which is an important feature of the present inventionas discussed below. The lower arm 38 furthermore is resiliently biasabledownwardly by a compression spring member 46 having one end pivotallyattached to the lower arm 38 and a second end pivotally attached to anupper spring bracket assembly 48 on the upper arm 30. Opener assembly 24generally includes a rotatable disk 50 for forming a furrow; a rotatablegauge wheel 52 for controlling furrow depth; and a seed tube assembly 54for receiving seed from the hose 22 and depositing the seed into thefurrow. Closing means shown in association with the opener assembly 24include a first press wheel 56 for pressing the seed into the furrow;and a second press wheel 58 for covering the seed with soil.

FIG. 2 shows the upper portion of opener arm assembly 28 in greaterdetail. In particular, the attachment of upper arm 30 to rockshaft 26utilizing U-bolt 34 threadedly engaged with nuts 60 is shown. The upperspring bracket assembly 48 is also shown. Referring also to FIGS. 3 and4, upper spring bracket assembly 48 includes a pair of bracket members62 and 64 preferably of plate metal construction, which brackets extendin parallel, spaced relation upwardly and rearwardly from a cavity 66formed in the upper arm member 30 which is preferably of cast metalconstruction, although tubular construction or a weldment could also beused. The bracket members 62 and 64 are secured in position on upper armmember 30 using pin members 68 which pass through holes 70 in thebracket members 62 and 64 and through holes 72 in the upper arm 30. Thepins 68 are retained in position in their respective holes using cotterkeys 74 for ease of assembly and disassembly. The spacing between themembers 62 and 64 is maintained using tubular spacer 76 in associationwith one of the pins, which spacer is of predetermined length. The upperend of spring 46 is pivotally mounted to the brackets 62 and 64 andretained by an upper spring retainer 78. Retainer 78 is preferably ofcast metal construction and includes opposed disk shaped ends mountedfor pivotal movement in holes 80 extending through bracket members 62and 64. Upper spring retainer 78 has a central bore 82 extendingtherethrough, which bore 82 slidably receives a spring guide rod 84which extends axially through spring 46. Rod 84 is used to raise andsupport lower arm 38 and the associated opener assembly 24 when the unitis in the raised or transport position, and also acts to guide themovement of spring 46. The upper end of rod 84 is threadedly engagedwith a nut 86 for retaining rod 84 in central bore 82 when the opener isnot engaged with the ground. Spring 46 is maintained in generallycoaxial relation with rod 84 by an annular spring guide member 90 whichis of a predetermined length selected to limit the maximum upward axialtravel of rod 84 by engagement with upper spring retainer 78, and thusthe upward pivotal movement of lower arm 38 with respect to upper arm30. The lower end of rod 84 passes through a lower pivot pin 92 mountedfor pivotal movement in holes 94 extending through a bifurcated portionof forward end portion 40 of lower arm 38 which is preferably a castmetal member, although again, other constructions could likewise beused. The lower end of spring 46 is engaged by an annular washer 96.Washer 96 is maintained in spaced relation to lower pivot pin 92 by anannular spacer assembly 88, both of which member 96 and assembly 88receive rod 84 through a central bore therethrough. Rod 84 furthermoreincludes an enlarged head or nut 100 on the lower end thereof to preventdisengagement of rod 84 from pivot pin 92 when raising and supportingthe lower arm. Referring to FIG. 5, annular spacer assembly 88 alsoprevents relative rotation between rod 84 and lower arm 38, and includesa spacer 98 and a plate member 102 welded to the outer surface of thespacer, which assembly is positionable in the bifurcated portion of theupper end 40 of lower arm 38 for preventing rotation of the spacertherein. A roll pin 104 installed in holes 106 through the spacer 98 andalso through a transverse hole extending through rod 84 (not shown)prevents rotation between the rod 84 and the spacer. Roll pin 104 alsoprevents rod 84 from falling through the spacer assembly 88 when theunit is in the field position with the spring compressed, for smootherpivotal operation of the drag arm assembly.

Referring again to FIG. 1, opener assembly 24 is shown in its down orfield position engaged with the soil 44. In this position, spring 46will usually be in some state of compression, which compression incombination with the weight of the unit provides downwardly directedpressure to enable disk 50 to open a furrow in the soil. This downwardlydirected pressure can be lessened or increased to varying degrees byrotation of rockshaft 26 which affects compression of the spring. Forinstance, rotation of rockshaft 26 in the clockwise direction willprovide less compression of the spring so as to lessen down pressure,whereas rotation in the counterclockwise direction will increasepressure. Rotation of the rockshaft is hydraulically controlled in theconventional manner (not shown). In conventional till, since the groundwill be generally loose and easy for the disk 50 to penetrate, little orno hydraulically directed down pressure may be required, and in manycases the weight of the opener assembly 24 will provide down pressuresufficient to open the desired furrow.

FIG. 6 shows an opener assembly 24, which is the same as that of FIG. 1except that it is a left hand model. That is, it is the same except thatit faces the opposite direction. Again, the forward direction isindicated by the arrow A. This view shows the bifurcated forward endportion 40 of lower arm 38, as well as a bend in the shape of the armwhich orients the axis of disk 50 and gauge wheel 52 at a small offsetangle with respect to the direction transverse to the forward directionA. An offset angle from about 4° to about 6° has been found to work wellin most conventional till applications and an angle of about 5° ispreferred. The offset angle is important as it positions surface 108 ofdisk 50 in a slightly forward orientation with respect to the directionof travel whereas opposite disk surface 110 faces slightly rearwardly,the same being true for the corresponding surfaces of gauge wheel 52.With opener assembly 24 in its field position and being moved in theforward direction, disk 50 turns through the soil and opens a furrow ortrench corresponding in shape to the forwardly facing profile of thatportion of the disk engaged with the soil, the depth of the trench orfurrow being determined by the position of the bottom of gauge wheel 52with respect to the bottom of the disk, as will be shown. Gauge wheel 52additionally serves to control or limit soil disruption on the side ofthe furrow formed by the forward face 108 of the disk.

First press wheel 56 of the closing means is located rearwardly of disk50 and is mounted for rotation about spindle 112 located adjacent therearward end of a first closing wheel arm 114, the forward end of whichis mounted for pivotal movement in the direction shown in FIG. 7 aboutspindle 116 mounted adjacent the reward end of lower arm 38. First presswheel 56, importantly, is sufficiently narrow so as to be able to followin the bottom of the trench or furrow formed by disk 50 and positivelypress seed discharged by seed tube assembly 54 into the bottom of thefurrow. A press wheel 56 of lightweight, stamped metal, non-pneumaticconstruction having a width of no more than about 1/2 inch has beenfound to work best. Second press wheel 58 is similarly mounted forrotation on a short transverse arm 118 mounted adjacent the rear end ofsecond closing wheel arm 120, the forward end of which arm 120 ismounted for pivotal movement in the direction shown in FIG. 7 aboutspindle 122 also mounted adjacent the rearward end of lower arm 38.Second press wheel 58 can be positioned to follow along the gauge wheelside of the furrow to move soil into covering relation to the seedfurrow, as will be discussed.

Other components of opener assembly 24 include a quadrant 124 mountedadjacent the rearward end of lower arm 38. Quadrant 124 has an elongatedslot 126 extending generally along the length thereof. Adjacent oppositesides of slot 126 are a plurality of offset holes 128. A T-shaped handle130 mounted on the distal end of a gauge wheel adjusting rod 132 (FIG.7) has downwardly extending pins 134 (also FIG. 7) engageable with holes128 on opposite sides of slot 126 for positioning T-handle 130 andassociated adjusting rod 132 in a number of positions with respect toquadrant 124. This is for adjusting furrow depth, as will be explained.Further with regard to the closing means, first and second press wheel56 and 58 are resiliently biased in the downward direction by springmembers 136 and 138, respectively, which spring members are alsoadjustable as will be explained. Additionally, first press wheel arm 114on which first press wheel 56 is pivotable or otherwise mounted ismovable somewhat about spindle 116 in the transverse direction to enablethe press wheel to follow the center of a furrow during sidewardmovements such as gradual turning of the unit 10 in the field. Secondpress wheel 58 is mounted for rotation on the short shaft (not shown)which is retained in a bore in transverse arm 118 by engagement withbolt 140 threadedly mounted on arm 118. The transverse position ofsecond press wheel 58 can optionally be made adjustable by making bolt140 engageable with the short shaft at more than one location along itslength to enable moving wheel 58 inwardly and outwardly telescopicallywith respect to arm 118. A grass shield 142 is mounted using screw 144on lower arm 38 in covering relation to the forward end portion ofopener assembly 24 to prevent trash and other material from gettingjammed and tangled with the respective components thereof.

Referring to FIG. 7, first press wheel spindle 112 is secured to presswheel arm 114 by passage through an aperture therethrough and threadedengagement with a nut 146. Spindle 116 is similarly secured in thecentral aperture of a bushing 148 by nut 150. Bushing 148 is mounted ona mounting plate member 152 which is secured to the rearward end oflower arm 38 with bolts 154. Spring 136 is a coil spring which wrapsaround the outer surface of bushing 148 and has one end that actsagainst the distal end of arm 114 and another end that acts againstplate 152 to exert down pressure against press wheel 56 when in thefield position. Similarly, spindle bolt 122 for the second press wheelpasses through a central aperture in bushing 156 mounted on plate 152and is secured in position by threaded engagement with nut 158. Spring138 is a coil spring which wraps around bushing 156 and includes anelongated end portion selectably engageable with slot detent members160-164 located adjacent the distal end of arm 120 for applyingdifferent degrees of down pressure against second press wheel 58. Spring138 can also be left disengaged from all of the detent members toprovide a no down pressure setting. The position of detent members160-164 at a rearward location adjacent the end of the arm 120 providesease of adjustablity without tools.

Gauge wheel 52 is mounted for rotation on a spindle 166 mounted on thedistal end of a pivotable arm 168. Arm 168, in turn, is mounted forpivotal movement about a central shaft 170 mounted in an apertureextending through the rearward end of lower arm 38. A second arm 172 isattached to arm 168 for joint pivotal movement therewith about centralshaft 170. Second arm 172 includes a distal end portion which is movablein slot 126 between the adjacent end of quadrant 124 and T-handle 130.When in the field position with the outer perimeter of gauge wheel 52shown in phantom lines resting on the ground surface 174, arm 168 andarm 172 will be jointly pivoted in the clockwise direction to a positionwherein arm 172 is in engagement with T-handle 130 thereby setting themaximum depth of penetration of disk 50 also shown in phantom lines,into the ground, which depth will also be the furrow depth and isdesignated by the letter X. Furrow depth is easy to adjust usingT-handle 130 and requires no tools. T-handle 130 is biased by aninternal spring member (not shown) toward quadrant 124 and when no downpressure acts against the gauge wheel, arm 172 will be resting againstthe end of slot 126 so that the T-handle can be manually lifted androtated about central shaft 170 to engage pins 134 with any selectedslots 128 on the quadrant for changing the furrow depth X. Typically,for most applications the furrow depth X will be within a range fromabout 1/2 to about 4 inches, and using the means shown can be adjustedin 1/4 inch or less increments.

FIG. 8 shows mounting plate 152 detached from arm 38. Mounting the presswheel arm members 114 and 116, spring members 136 and 138, and presswheels 56 and 58 (not shown) on a detachable mounting plate member asshown provides ease of assembly and disassembly and interchangeabilityof components in the field for shorter downtimes for service and thelike.

Referring to FIG. 9 which shows the right hand opener 24 of FIG. 1, thedisk 50 is shown rotatably mounted to the rearward end of arm 38 on ahollow spindle 176. The tapered end of hollow spindle 176 is receivedthrough an opening on the arm and is secured thereto by a first nut 178and set screw 180. The disk 50 is attached to bearing housing 182 bybolts 184. The bearing housing 182 rotates with respect to spindle 176,and the bearing housing 182 is secured in its horizontal position withrespect to the spindle 176 by a second nut 178 and a second set screw180. The bearing housing 182 encloses and protects a pair of seals 186and bearings 188 which are held in position by an annular lip or snapring 190. With reference to the discussion above relating to the angularorientation of disk 50, the hollow spindle 176 has an axis 192 that isdisposed at the above described 4° to 6° angle with respect to atransverse reference line 194. Since the disk 50 is disposedperpendicular to spindle 176, it will be disposed at a similar anglewith respect to the direction of travel.

FIG. 9 also shows the gauge wheel 52 in greater detail. As discussedabove, gauge wheel 52 is mounted for rotation on spindle 166 which ismounted adjacent the distal end of arm 168 attached to one end ofcentral shaft 170. As shown here, shaft 170 passes through hollowspindle 176 and an aperture through lower arm 38. Gauge wheel 52includes a flexible tire 198 mounted on an inner and outer wheels 200and 202, which inner and outer wheels are mounted on a sealed bearing204 rotatable on spindle 166. Tire 198 of gauge wheel 52 has an inneredge or blade portion 206 that engages front face 108 of disk 50 forwiping or scraping the disk face during rotation of the respectivemembers.

Referring to FIGS. 10 and 11, the seed tube assembly 54 is shown ingreater detail. Seed tube assembly 54 includes a mounting arm 208 whichis adjustably clamped adjacent the disk side of the rearward portion ofarm 38 by retaining plate 210. Retaining plate 210 is threadedly engagedwith bolts 154 which pass through holes in arm 38 and through elongatedslots 212 in the mounting arm. Seed tube assembly 54 further includes ahollow or tubular seed tube 213 and a runner or shoe 214 pivotallyattached to mounting arm 208 by bolt 216. The lower end portion of seedtube 213 as well as runner or shoe 214 are biased against rearward face110 of disk 50 by a spring 218 which is preferably a coil springattached between the upper end of mounting arm 208 and an upper portionof the seed tube 213, although other types of springs could also beused. The upper end of seed tube 213 attaches to the bottom end of hose22 using a hose clamp or other suitable means (FIG. 1) and includes aseed tube inlet opening 220 for receiving seed from the hose. Seed tube213 provides a straight, un-obstructed conduit of passage for seedtherethrough, the seed exiting form the tube through an outlet opening222, as shown by the arrow B. The outlet opening 222 is angularlyoriented with respect to the longitudinal axis of the tube 213 so as toopen both downwardly and rearwardly with respect to the forwarddirection identified by the letter A in FIG. 10. Runner 214 is locatedforwardly of the seed tube lower portion and includes a downwardly andrearwardly curving blade-like leading edge portion 224 which ispositioned in close relation to rearward surface 110 of disk 50. Runner214 serves to hold and prevent loose top soil adjacent that side of thefurrow from falling into the furrow in advance of seed depositedtherein, but is sufficiently narrow so as to move through the furrowbehind or in the shadow of that portion of the disk engaged with thesoil so as to no further significantly form, firm or otherwise enlargethe furrow or disturb the adjacent soil. That is, the shadow of the diskis defined by the profile of the disk when viewed from the rear, and therunner 214 as well as the lower portion of the seed tube 213 and otherlower seed tube components are located in this shadow or profile whenalso viewed from the rear. In this regard, FIG. 9 shows seed tube 54 andrunner 214 in phantom, no portion of the lower portion of which extendsoutwardly of the profile or shadow of that portion of disk 50 which willbe engaged with the ground, represented by rearwardly projecting line225.

The downwardly and rearwardly curving leading edge 224 of runner 214 isanother important feature. Most importantly, the downwardly andrearwardly curving blade-like edge enables the runner to have a taperedprofile shape which gets narrower towards the bottom end terminating atthe blade-like edge. This enables the runner to be more easily conformedto the profile shape of the disk 50 to thereby avoid any significantcontact with a furrow wall formed thereby, which furrow wall will have ashape generally corresponding to the profile shape of the disk leadingedge. Because the runner does not significantly engage the furrow wall,it can be of relatively lightweight construction, such as from sheetmetal, nylon and other polymers and other materials. The downwardly andrearwardly curving shaped also enables maintaining at least most of therunner out of contact with the bottom of the furrow, such that therunner places no significant drag on the assembly as it moves throughthe furrow and will not be inclined to collect mud under wet conditions.The above described runner shape has also been found to eliminate theneed for any rearward extension or runner aft of the seed tube outlet,which again reduces drag, and also side draft forces when turning.

Still another important feature of the present invention is means toprevent soil from backing up into and clogging the seed tube outlet 222mounted just rearwardly thereof. The anti-clogging means include a flapmember 226 which as shown in FIG. 11 generally conforms to the profileshape of seed tube outlet opening 222 so as not to drag through thefurrow. The flap member is pivotally mounted on the seed tube withadjustable hinge 228. With the opener in the field position and movingforwardly as designated by the arrow A in FIG. 10, flap 226 will beoriented in an open position about like that shown in hidden lines, soas not to obstruct or otherwise hinder the outflow of seed from seedtube outlet 222. In the event the opener is moved in the rearwarddirection, flap 226 will position itself about as shown in solid linesto prevent the passage of soil and other matter into outlet opening 222.As mentioned previously, seed tube assembly 54 is adjustablypositionable with respect to lower arm 38 by loosening bolts 154 andrepositioning the seed tube assembly in a more upward or downwardposition, as desired. This feature is useful for fine tuning seedplacement in the furrow, and also for adjusting seed tube position asthe disk wears. As also noted above, the seed tube and runner portion ofassembly 54 is pivotable relative to mounting bracket 210 and the lowerend is resiliently urged against rear disk face 110 by spring 218. Thisenables runner 214 to scrape and clean disk face 110 as it rotatesthrough the soil, and allows the seed tube assembly to be resilientlyurged away from disk 110 to enable the passage of trash and other matterbetween the seed tube assembly and disk. Also carried on arm 38 isanother shield 228 that prevents trash and other matter from jamming andpreventing pivotal movement of the seed tube assembly.

Referring to FIGS. 12 and 13, second press wheel 58 is mounted forrotation on arm 118 for pushing or otherwise moving soil into coveringrelation seed located in the furrow. For optimal performance, asmentioned above the transverse position of second press wheel 58 can bemade adjustable by loosening adjusting bolt 140 and sliding the spindleon which the wheel is mounted (not shown) longitudinally to a desiredposition in tubular arm 118 and retightening adjusting bolt 140.Additionally, transverse arm 118 can be adjustably positioned withrespect to longitudinal arm 120 with adjusting bolt 230, by loosening ofadjusting bolt 230 and rotating arm 118 thereby orienting closing wheel58 at a number of different angular orientations with respect to ground44. This is to enable adjusting the wheel to provide a relativelyprecise amount of coverage for the seed. In this regard, incrementalmarkings such as shown at 231 can be provided on arms 118 and 120 forreferencing the rotational position of arm 118 with respect to arm 120and to enable more easily adjusting the arms of a number of openerassemblies to the same setting. The construction and shape of secondpress wheel 58 is also important. Second press wheel 58 is preferablymade from a lightweight material such as aluminum and has an outer rimportion 232. Outer rim portion 232 can be integrally formed, or can be areplaceable member made from steel or other longer lasting material.Outer rim portion 232, importantly, has a double beveled shape formed byangularly related surfaces 234 and 236. The double beveled shape of edge232 enables surface 234, which is the leading surface as the wheel movesacross the ground, to engage the ground and push a desired amount ofsoil into the furrow. Surface 236 is the trailing surface and itsangular relationship to leading surface 234 enables it to be positionedin generally parallel relation to the surface of the ground. This isimportant as it makes the press wheel less likely to displace a longribbon or strip of soil in wet conditions, and less likely to plow insofter, dryer soils.

FIG. 14 shows another embodiment of an opener assembly 238 havinggenerally the same component parts and functioning generally in the samemanner as opener assembly 24 discussed above. Like components of openerassembly 238 corresponding to those of opener assembly 24 are designatedby the same reference numbers. Opener assembly 238 primarily differsfrom opener assembly 24 in the provision of gauge wheel pivot arm 240,and first and second press wheel support arms 242 and 244, which are allmounted for pivotal movement about the axis of a single spindle or bolt246 mounted to a mounting plate 248. Mounting plate 248 is mountable onthe rearward portion of lower arm 38 in the same manner as describedabove. Gauge wheel 52 is mounted for rotation on a spindle 250 locatedadjacent the distal end of arm 240. Mounted for joint pivotal movementwith gauge wheel mounting arm 240 is a gauge wheel adjusting arm 252which has a distal end portion positioned in slot 126 of quadrant 124and movable between the end of the slot and T-handle 130 in the mannerdescribed above with respect to arm 172. Further, the press wheelmounting arms 242 and 244 are pivotable in generally in the same manneras described above with respect to arms 114 and 120, and include a firstspring member 254 (FIG. 15) for resiliently biasing first press wheelarm 242 in the downward direction, and a second spring member 256 forresiliently biasing second press wheel mounting arm 244 in the downwarddirection. Spring member 256, like spring member 138, includes anelongated portion selectively engageable with slot or detent members160-164 on arm 244 for adjusting the spring force exerted thereagainst.

FIG. 15 is another view of the opener arm assembly 238 showing thelocation and orientation of the respective components thereof, as wellas their mounting positions with respect to opener arm 38. Gauge wheelsupport arm 240 (FIGS. 14 and 16) and adjusting arm 252 are jointlymounted on the end of spindle 246 located adjacent gauge wheel 52. Thespindle 246 extends from the arms 240 and 252 through an opening inmounting plate 248 and past the plate a predetermined distance. Thepress wheel mounting arms 242 and 244, as well as springs 254 and 256,and T-handle adjusting rod 132, are mounted on the side of spindle 246opposite the gauge wheel. The above named members are retained onspindle 246, and spindle 246 is maintained in position on mounting plate248, by washer 258 and nut 260. The position and orientation of disk 50as well as gauge wheel 52 at an offset angle with respect to the forwarddirection indicated by the arrow A is shown, as is the relativepositions of first and second press wheels 56 and 58.

FIG. 16 shows the internal arrangement and order of assembly of thecomponents of opener arm assembly 238. Gauge wheel mounting arm 240 andadjusting arm 252 are shown as integrally formed on one end of spindle246. Spindle 246 further includes an elongated cylindrical portion 262of predetermined length which extends from the juncture with arms 240and 252 through the central bore of bushing 264. The cylindrical portion262 terminates at an annular shoulder 266 adjacent a threaded endportion which receives washer 258 and nut 260. Bushing 264 is mounted inan opening extending through mounting plate 248 and serves as a bearingfor the spindle 246. Bushing 264 is slightly longer that the cylindricalportion 262 of spindle 246 such that washer 258 bears against thebushing when nut 260 is tightened. Press wheel arm 244 includes an innercylindrical portion 268 which mounts in overlaying relation to bushing264, and an outer cylindrical portion 270 spacedly related to innerportion 268. The outer surface of bushing 264 serves as a bearingsurface for the cylindrical portion 268, and the outer surface of innercylindrical portion 268 serves as a bearing surface for a cylindricalmounting portion 274 of press wheel arm 242, which cylindrical portion274 is sized for locating in the annular shaped cavity defined betweeninner and outer cylindrical portion 268 and 270 of the member 244.T-handle adjusting rod 132 includes an annular shaped mounting portionwhich also mounts on the outer surface of bushing 264, and importantlyis retained in position thereon by washer 258 and nut 260. In thisregard, it should be noted that washer 258 abuts the end of bushing 264so as to provide some end play for the members mounted thereon. This isimportant as it provides retention of all of the members on spindle 246,without interfering with the free pivotal movement thereof. It can alsobe seen from this arrangement, that gauge wheel mounting arm 240 andadjusting arm 252 can be pivotable independent of press wheel arms 242and 244, while sharing a pivotal axis therewith. To facilitate freemovement of the respective pivotal members, a grease fitting (not shown)can be mounted in communication with passageway 278 which extendspartially through spindle 246 and communicates with cross passages 280extending through the various members for providing grease to thevarious bearing surfaces. To further facilitate a compact and easy toservice assembly, springs 254 and 256 are preferably coil spring memberswhich wrap around the outer surface of press wheel mounting arm 244. Itcan be seen from this figure that the removal of the single nut 260enables easy disassembly of the gauge wheel, springs and press wheelmounting arms, in a matter of moments. Additionally, like severalmembers of the assembly 24 mounted on mounting plate 152, the componentsof opener assembly 238 mounted on mounting plate 248 are easilydetachable from arm 38 as a unit by removing mounting bolts 154.Referring again to FIG. 14, note that quadrant 124 and T-handle 130 arelocated adjacent the rearward portion of opener assembly 238 aft of seedtube assembly 54. This location makes adjustment of planting deptheasier from the rear of the unit compared to the location on openerassembly 24 shown in FIG. 7. Still referencing FIGS. 14 and 7, it can benoted that the distance between gauge wheel center 250 and disk center170 of assembly 238 (FIG. 14) is shorter than the distance between gaugewheel center 166 and disk center 170 of assembly 24 (FIG. 7). Anadvantage of a small distance between the gauge wheel axis and disk axisis that as the opener assembly pivots with arm 38 about flange bolt 42,there will be even less variation in planting depth, although the lowpivot point of arm 38 already acts to greatly minimize this problem, asexplained elsewhere herein. It should be further noted with regard toopener assembly 238 that gauge wheel adjusting arm 240, first presswheel mounting arm 242, and second press wheel mounting arm 244 need notall be mounted for pivotal movement about the same axis. In this regard,it is recognized that any one of the respective members could be mountedfor pivotal movement about a separate axis, although this is not apreferred embodiment.

In operation, when implement 10 is towed in the forward directionindicated by the arrow A and rockshaft 26 is rotated counterclockwise toengage either opener assembly 24 or opener assembly 238 with the soil44, as shown in FIG. 1, disk 50 will open a relatively narrow furrow inthe soil. Gauge wheel 52 will establish the penetration depth of disk 50into the soil, and thus the furrow depth, and seed tube assembly 54 willmove through the furrow in the shadow of disk 50 depositing seed in thebottom of the furrow at a rate controlled by metering means 20 and thepulling speed. First press wheel 56, which is preferably a relativelynarrow member sufficiently small to follow along in the bottom of thefurrow, is biased downwardly so as to firmly press the seed into thebottom of the furrow. Second press wheel 58 trails first press wheel 56adjacent one side of the furrow, and its double beveled shaped and angleenable it to precisely scrape or move a desired amount of soil intocovering position over the seed. Importantly, the adjustability of thesecond closing wheel 58 in terms of both position, orientation anddownward biasing pressure, enables the precise placement of soil overthe seed in both loose soil and wet conditions. Further, the lightweight of the second press wheel enables it to maintain relativelyconsistent contact with the soil, even at high pulling speeds. Asmentioned above, the lower portion of seed tube assembly 54 ispositioned and sufficiently narrow so as to follow in the shadow orprofile in disk 50 without significantly forming or firming the side ofthe furrow and acts only to keep loose soil out of the furrow longenough for seed to be deposited in the bottom of the furrow. Anotherimportant operational feature of the present invention is the opener armassembly 28. The relatively low pivot point of lower arm 38 is importantas it enables lower arm 38 to be oriented when in the field position ata relatively small angle with respect to horizontal in a arrange fromabout 0° to about 20°, and preferably in a range less than 15° or so.This enables the opener assembly 24 to maintain a relatively constantorientation and relationship with respect to the soil as lower arm 38 ispivotally displaced, enabling the opener to pass over surfaceirregularities and the like without significantly affecting furrow depthand seed placement. Also importantly, this arm assembly geometry enablesrockshaft 26 to be rotated in the counterclockwise direction to positionupper arm 30 in even a substantially vertical or forwardly directedorientation without significantly affecting the orientation of lower arm38 and opener assembly 24. This is a particularly important feature ofthe present invention. Also notable, the freedom of movement of springguide rod 84 relative to upper spring bracket assembly 48 enables arelatively wide range of pivotal movement of lower arm 38 without rod 84extending below the pivot point 42, which is a desirable feature whentraversing fields containing standing trash as the rod is not likely tocontact the trash. Still another feature of the present invention is therelatively small offset angle of disk 50, preferably about 5° or less,which forms a narrower furrow than other known planting units andenables gauge wheel 52 to be relatively narrow such that the overallwidth of the unit can be correspondingly small and a greater number ofplanting units can be mounted on a rockshaft of a given length, enablingplanting in closer rows. The small disk offset angle in combination withthe narrowness of the lower portion of the seed tube assembly causesless drag when pulled through the soil. This results in less wear andenables the respective components to be of lighter construction, all ofwhich features enable an implement utilizing planting units constructionaccording to the present invention to be pulled with a smaller tractor.Additionally, the lighter weight and shorter height capabilities of thepresent planing unit can be combined to provide an implement that hasless of a tendency to "walk" at higher pulling speeds.

FIG. 17 shows still another embodiment of an opener assembly 282 havingmany of the same component parts and functioning in the same manner asopener assemblies 24 and 238, and, again, like components of openerassembly 282 corresponding to those of opener assembly 24 and openerassembly 238 are designated by the same reference numbers. Openerassembly 282 primarily differs from the previously discussed openerassemblies in the provision of a draw bar assembly 284 including a lowerarm 286 which carries a disk bearing assembly 288 internally therein forrotatably supporting disk 50, as best shown in FIG. 18. Draw barassembly 284 additionally includes an upper arm 30 fixedly attached to arock shaft 26 using U-bolts 34 secured in position around the rock shaft26 with nuts 60 (not shown) in the conventional manner, as describedabove. Rock shaft 26 forms part of an implement such as the seed drill10 discussed above (not shown). Lower arm 286 has a forward end 290pivotally connected to lower end 36 of upper arm 30 with pivot bolt 42and is biasable in the downward direction by compression spring 46mounted between an upper spring bracket assembly 48 mounted to upper arm30 and a lower pivot pin 92 mounted to lower arm 286, all as previouslydescribed above.

Referring also to FIGS. 18 and 19, lower arm 286 is an elongated memberof rigid, tubular construction and includes a rearward end 292 oppositeforward end 290 and an intermediate portion 294 located therebetween,which intermediate portion 294 includes a bend which orients rearwardend 292 at a small actuate angle with respect to the forward directionof travel of the implement on which the opener assembly 282 is mounted,which direction of travel is designated by the arrow identified by theletter A as before, and the preferred small actuate angle beinggenerally about 5°, as best shown in FIG. 19. Importantly, referringmore particularly to FIG. 18, rearward end 292 of lower arm 286 carriesdisk bearing assembly 288 in a transversely mounted cylindrical shapedtubular bearing housing 296, which serves to orient the plane of disk 50at a corresponding small acute angle of about 5° to the direction oftravel A. Bearing housing 296 includes an internal cylindrical cavity298 extending therethrough adapted for receiving disk bearing assembly288 and an annular flange 300 extending around cavity 298 for centeringthe disk bearing assembly in cavity 298. Disk bearing assembly 288includes two bearings 302, an annular spacer 304, inner and outer dustseals 306 and 308, and nut 310, all of which mount on a cylindricalspindle 312, one end of which spindle is mounted to disk flange 314.Spindle 312 has a threaded end opposite disk flange 314 threadedlyengaged by nut 310 which retains the spindle in the bearing housing asshown. Disk 50 is mounted to the surface of disk flange 314 oppositespindle 312 with flat head screws 316 which pass through countersunkholes in disk 50 as shown. This mounting arrangement including the useof countersunk flat head screws 316 is important as it enables the edgeof the rubber or polymeric material tire portion of gauge wheel 52 topass over screws 36 without catching or tearing on the screws to providean increased range of adjustability for the gauge wheel. Carryingbearing assembly 288 internally in rearward end 292 of lower arm 286 isalso important by itself as it enables the overall width of openerassembly 282 to be reduced by an amount equal to the about one half thewidth of the bearing assembly as compared to the above discussed openerassemblies 24 and 238 both of which locate the bearing assembly for thedisk between the disk and the lower arm. This in turn facilitates thelocation of a plurality of the openers 282 in closely spaced,side-by-side relation, as illustrated in FIG. 19, which enables plantingin more closely spaced rows, for instance, 6 or 7 inches apart or less.

Additional features of opener assembly 282 that facilitate the mountingand operation of adjacent opener assemblies in more closely spaced,side-by-side relation include the provision of a quadrant 124 mountedover the rearward end of a mounting plate 318 attached to the rearwardend of lower arm 286. Quadrant 124 includes the same components asdiscussed above including an elongated slot 126 with offset holes 128 oneither side, along with a downwardly biased T-shaped handle 130 havingpins 134 (not shown) selectively engageable with holes 128 for limitingthe travel of the distal end of a gauge wheel adjusting arm 252 locatedin slot 126 to enable adjusting the planting depth of the opener aspreviously explained. T-shaped handle 130 is mounted on an adjusting rod132 mounted for rotation about a rear spindle 246 mounted adjacent therearward end of mounting plate 318 below quadrant 124. Similarly, aspreviously described above with reference to FIGS. 14-16, first andsecond press wheels 56 and 58 are mounted for rotation on press wheelarms 242 and 244, respectively, which are also mounted along withsprings 254 and 256 on spindle 246 and held in position with nut 260.

Like the previous embodiments 24 and 238, opener assembly 282additionally includes a seed tube assembly 54 which can be adjustablymounted to the opener assembly in the above described manner, or mountedas shown in FIG. 17, using a single bolt 320 which passes through a slot322 through plate 318 and is threadedly engageable with a threadedaperture (not shown) on the seed tube assembly 54 to bear against awasher 324 and frictionally hold the seed tube assembly in a desiredvertical position.

FIGS. 20, 21 and 22 are a left hand side view, a top view and a partialcross-sectional view, respectively, of still another embodiment of anopener assembly 326 having many of the same component parts andfunctioning in the same manner as opener assemblies 24, 238 and 282,again, like components of opener assembly 326 corresponding to those ofthe previously described opener assemblies being designated by the samereference numbers. Opener assembly 326 primarily differs from thepreviously discussed opener assemblies in the provision of a diskbearing assembly 328 for rotatably supporting disk 50 located in acavity 330 of gauge wheel 52 to reduce the overall width of the opener,and in the provision of an alternative seed tube assembly and analternative quadrant assembly for adjusting planting depth. Theconstruction of gauge wheel 52 is discussed above and is shown in FIG.9. Disk bearing assembly 328 is mounted on a spindle 332 (FIG. 22) whichis fixedly mounted so as to project transversely from a mounting plate334 mounted to the rearward end of a lower drag arm 336 (FIG. 21). Lowerdrag arm 336 mounts for pivotal movement to an upper arm of a drag armassembly (not shown) and is biasable downwardly in the conventionalmanner as described above by a spring member (also not shown) and likethe previously described lower drag arms, drag arm 336 is bent at abouta 5° angle to the direction of travel of an implement on which theopener assembly is mounted. Opener assembly 326 likewise includes firstand second press wheels 56 and 58 mounted for rotation on press wheelarms 242 and 244, respectively, press wheel arm 242 being pivotallyattached to mounting plate 334 separately at a lower position withthreaded bolt 340 threadedly engaged with the mounting plate, whilepress wheel arm 244 is pivotally mounted about a spindle 342 and held inposition with nut 344 threadedly engaged therewith. Like in the previousembodiments, press wheel arm 242 is biased downwardly using a springsuch as the spring 254, deleted here for clarity, press wheel arm 244being biased downwardly using a spring 345, one end of which windsaround spindle 342 and the other end of which engages arm 244.

Turning to FIG. 22, disk bearing assembly 328 includes two bearings 346,a spacer 348 and a dust seal 350, all mounted on spindle 332 and securedin position with a spindle nut 352 threadedly engaged onto a threadedend of spindle 332. The above described components 346-352 are containedin a cylindrical inner cavity 354 of a bearing housing 356, one end ofwhich is covered by a conventional dust cap 358 frictionally engagedwith the bearing housing. Bearing housing 356 additionally includes aninner annular flange 360 extending around inner cavity 354 for centeringbearings 346 on spindle 342, and a disk mounting flange 362 extendingtherearound opposite the threaded end thereof, which disk mountingflange 362 includes an array of spaced threaded holes 364. Disk 50includes a central hole 366 therethrough adapted for receiving bearinghousing 356 and an array of counter sunk holes 368 therearoundcorresponding in location to threaded holes 364, which holes 364 and 368receive flat head screws 316 for securing disk 50 to disk mountingflange 362. Importantly, as noted above, bearing housing 356 is locatedin cavity 330 of gauge wheel 52 such that the overall width of openerassembly 326 is reduced by about one half of the width dimension of thebearing housing as measured between the end of the dust cap 358 andplate 334, which like in the case of opener assembly 282, enables theplacement of the opener assemblies in much closer spaced side by siderelation.

Referring more particularly to FIG. 20, gauge wheel 52 is shown inphantom to reveal a gauge wheel mounting arm 370, one end of which gaugewheel mounting arm 370 mounts for pivotal movement about spindle 342,the opposite end of which has a hole 372 therethrough for receiving amounting bolt (not shown) for mounting the gauge wheel for rotation toarm 370. A gauge wheel adjusting arm 374 is fixedly attached to gaugewheel mounting arm 370 for rotation therewith about spindle 342 andincludes an adjusting pin 376 having one end located in a slot throughadjusting arm 374 and an opposite end selectively insertable into aplurality of holes 378 (FIG. 21) of a quadrant 380 mounted abovemounting plate 334. Adjusting pin 376 is biased downwardly by a spring(not shown) located in a spring housing 382 on adjusting arm 374,adjusting pin 376 being manually movable upwardly from engagement withquadrant 380 to allow the joint rotation of gauge wheel adjusting arm374, gauge wheel mounting arm 370 and gauge wheel 52 about spindle 342as shown by the arrow B for selecting a desired planting depth, pin 376being insertable into a selected hole 378 and engageable with quadrant380 for preventing such pivotal movement to thereby select a desiredfixed planting depth. It should be noted here that spindle 342, likedisk bearing assembly 328, projects into cavity 330 of gauge wheel 52,cavity 330 being large enough such that the gauge wheel is movablethroughout a wide adjusting range for changing planting depth withoutcontacting the inner rim of gauge wheel 52.

Referring also to FIG. 23, opener assembly 326 includes an optional seedtube assembly 384. Seed tube assembly 384, like seed tube assembly 54,includes a seed tube 213, the upper end of which attaches to the bottomend of a seed hose in the conventional manner (FIG. 1) and a seed tubeinlet opening 220 for receiving seed from the hose. Seed tube 213extends between mounting plate 334 and disk 50, and additionallyincludes an outlet opening 222 for the discharge of seed or othermaterial into a furrow formed by the opener, the outlet opening beingangularly oriented as discussed above. Seed tube assembly 384additionally includes a seed tube runner 214 attached to seed tube 213,which seed tube runner 214 includes a curved leading edge 224 whichextends upwardly and forwardly from outlet opening 220 to a top edge386, and an outer surface 388 which extends from top edge 386 andleading edge 224 to seed tube 213, outer surface 388 serving to preventloose soil from entering a furrow in advance of seed or other materialexiting outlet 222 in the manner described above, and serving to preventtrash and debris from entering and being lodged between the seed tubeassembly 214 and bearing housing 356. Additionally, top edge 386 isrelatively sharp and serves to scrape and clean the surface of disk 50.Runner 214 further includes a hinged mounting assembly 390 for mountingthe seed tube assembly to lower drag arm 336, hinged mounting assembly390 including a slotted mounting plate 392 hingedly attached to runner214 and adjustably mountable to lower drag arm 336 using a bolt or boltsin the conventional manner (not shown), an important advantage of whichforward hinged mounting location being the ability of the more rearwardand lower portions of seed tube assembly 384 to move away from disk 50to allow the passage of trash and debris therebetween.

Here it should be noted that an additional feature of embodiments 238,282, and also 326, is the positioning of the pivot point for theadjustable gauge wheel 52 at a location that enables the lower edge ofthe gauge wheel to remain in at least close proximity to the exit pointof the disk 50 from the ground throughout the range of pivotaladjustment, represented by the arrow B in FIG. 20. This is a desirablefeature as it minimizes soil disruption cause by the exiting of the diskfrom the ground, thereby reducing moisture and chemical loss andproviding other advantages.

FIGS. 24 and 25 shown an optional hub cap 394 for installation on gaugewheel 52 to improve material flow between adjacent units. Hub cap 394 issized and shaped to fit in a recess of outer wheel 202 of gauge wheel 52and includes a plurality of counterbored holes 396 therethrough. Bolts398 are insertable through holes 396, and also through holes 400 throughwheel 52 and are threadedly engageable with nuts 402 for securing hubcap 394 on wheel 52. Alternatively, it is recognized that numerous otherfasteners can be used for attachment of hub cap 394 to wheel 52,including frictional fasteners and the like.

Thus, there has been shown and described planting unit constructionswhich fulfill all of the objects and advantages sought therefor. It willbe apparent to those skilled in the art, however, that many changes,modifications, variations and other uses and applications for thesubject planting units are possible and all such changes, modifications,variations and other uses and applications which do not depart from thespirit and scope of the invention are deemed to be covered by theinvention which is limited only by the claims which follow.

What is claimed is:
 1. An opener assembly movable forwardly over theground for opening a furrow therein comprising:a member adapted forconnection to an implement adapted for moving the opener assembly overthe ground; a generally flat disk connected to the member for rotationabout a disk axis offset at an angle to the direction transverse to theforward direction, the angled disk thus defining forwardly andrearwardly directed disk surfaces, the disk having a lower portionpositionable for penetrating the ground for opening the furrow thereinand an outer perimeter edge extending around the disk surfaces, theouter perimeter edge defining a disk profile when viewed from the reardirection, a seed tube located adjacent the rearward directed disksurface, the seed tube having a lower end portion located substantiallywithin the rear disk profile and including an outlet opening fordischarging material in the furrow located adjacent to the lower portionof the disk; and an extension supported adjacent the seed tube lower endportion and extending forwardly thereof closely adjacent the rearwardlydirected disk surface, the extension being shaped and sufficientlynarrow so as to be located substantially within the rear disk profileand to move through the furrow for preventing loose soil on the side ofthe furrow opposite the rearwardly directed disk surface from enteringthe furrow in advance of material discharged therein through the seedtube outlet opening with only minimal contact with the side of thefurrow.
 2. The opener assembly according to claim 1 wherein said memberadapted for connection to the implement comprises structure for pivotalconnection thereto.
 3. The opener assembly according to claim 1 whereinthe lower disk portion has a curved profile shape when viewed from therear direction, and the extension has an outer surface having a profileshape when viewed from the rear corresponding at least generally to thecurved rear profile shape of the lower disk portion.
 4. The openerassembly according to claim 1 wherein the extension further comprises aforwardly and upwardly curved leading edge portion located in at leastpartial abutting relation to the rearwardly directed disk surface. 5.The opener assembly according to claim 1 wherein the seed tube and theextension are jointly mounted to the opener assembly for hinged movementaway from the disk to allow the passage of trash and debris between thejointly mounted seed tube and extension and the disk.
 6. The openerassembly according to claim 5 wherein the seed tube and extension arehingedly mounted to the opener assembly at a forward location withrespect to the rearwardly directed disk surface.
 7. The opener assemblyaccording to claim 6 wherein the seed tube and the extension are jointlymounted for hinged movement about a hinge axis oriented at a no morethan a small acute angle to the vertical direction.
 8. The openerassembly according to claim 1 wherein the extension further comprises anupper edge portion in abutment to the rearwardly directed disk surfaceadapted for scraping soil therefrom.
 9. The opener assembly according toclaim 1 wherein the extension is made substantially of a polymermaterial.
 10. The opener assembly according to claim 1 furthercomprising a gauge wheel, and means connecting the gauge wheel to theopener assembly for rotation adjacent the forwardly directed surface ofthe disk about a gauge wheel axis generally parallel to the disk axis tolimit the penetration of the lower portion of the disk into the ground.11. The opener assembly according to claim 10 wherein the gauge wheel islocated closely adjacent to the forwardly directed disk surface and theforwardly directed disk surface has a central portion that issubstantially flat so as to allow positioning the gauge wheel adjacentthereto for limiting the penetration of the disk into the ground. 12.The opener assembly according to claim 1 wherein the member adapted forconnection to the implement further comprises a bearing assembly forrotatably supporting the disk, the bearing assembly being located atleast partially within the member.
 13. The opener assembly according toclaim 10 wherein the gauge wheel has a generally smooth, flat outersurface located opposite the disk.
 14. The opener assembly according toclaim 1 wherein the opener assembly has an overall transverse widthsufficiently small so as to allow connection to the implement inside-by-side, parallel relation with at least one other opener assemblyfor forming parallel furrows spaced from about six to about seven inchesapart.
 15. The opener assembly according to claim 10 wherein the meansconnecting the gauge wheel to the opener assembly includes an elongatedarm having a predetermined length and pivotally connected to the openerassembly at a location so as to position the bottom portion of the gaugewheel closely adjacent to a point where the disk edge exits the groundto minimize soil disruption at said point.
 16. The opener assemblyaccording to claim 10 wherein the gauge wheel has a cavity adjacent themember adapted for connection to the implement and the disk is mountedfor rotation on a bearing assembly located at least partially in saidcavity.
 17. A single disk opener assembly comprising a generally flatdisk supported for forward movement through the ground for forming afurrow therein, said disk having opposite disk surfaces oriented at asmall acute angle with respect to the forward direction and an outerperipheral edge extending around the disk surfaces defining a diskprofile when viewed from the rear, the outer peripheral edge including aforward edge portion having a lower portion positioned for imparting ashape to one side of said furrow, the disk surfaces including arearwardly facing disk surface having a lower portion positioned to belocated in spaced, opposed relation to said one side of said furrow,said opener assembly further including structure for depositing materialin said furrow having an outlet opening located adjacent a rearwardportion of said lower portion of said rearwardly facing disk surface,and a member extending forwardly from said structure beside said lowerportion of said rearwardly facing disk surface, said member terminatingrearwardly of said forward edge and having a shape and a sufficientlysmall width so as to be located substantially within said disk profileand to pass through said furrow with minimal contact with said one sideof the furrow while preventing soil from entering the furrow in advanceof material deposited therein through said outlet opening.
 18. Apparatusadapted for use with a single disk opener assembly for depositingmaterial in a furrow formed in the ground thereby, the single diskopener assembly having a generally flat disk supported for forwardmovement through the ground for forming the furrow oriented at a smallacute angle with respect to the forward direction, an outer peripheraledge defining a disk shadow when viewed from the rear and including alower forward portion positioned for imparting a shape to one side ofthe furrow, and a rearwardly facing lower surface portion positioned tobe located in the furrow in spaced opposed relation to said one sidethereof, the apparatus comprising:a member having an inlet opening forreceiving the material, a lower outlet opening for discharging thematerial, a conduit for the passage of the material between the inletand outlet openings, and a runner adjacent the outlet opening, themember being mountable to the opener assembly with the runner positionedbeside the rearwardly facing lower surface portion of said disk, saidrunner having a sufficiently narrow overall width so as to be locatedwithin the disk shadow and including an outer surface portion having ashape conforming closely to the shape of said one side of the furrow soas to substantially occupy the adjacent portion of the furrow to preventsoil from entering the furrow in advance of material discharged thereinfrom the outlet opening with only minimal contact with said one side ofthe furrow.
 19. Apparatus according to claim 18 wherein the runner has aleading edge portion having a downwardly and rearwardly curving shape.20. Apparatus according to claim 19 wherein the disk has a curvedforward most edge and the leading edge portion of the runner has acurved shape corresponding at least generally to a portion of saidcurved forward most edge.
 21. An opener assembly movable forwardly overthe ground for opening a furrow therein comprising:a member adapted forconnection to an implement adapted for moving the opener assembly overthe ground; a generally flat disk connected to the member for rotationabout a disk axis offset at an angle to the direction transverse to theforward direction, the angled disk thus defining forwardly andrearwardly directed disk surfaces, the disk having a lower portionpositionable for penetrating the ground for opening the furrow thereinand an outer perimeter edge extending around the disk surfaces, theouter perimeter edge defining a disk profile when viewed from the reardirection, a seed tube located adjacent the rearward directed disksurface, the seed tube having a lower end portion including an outletopening for discharging material in the furrow located adjacent to thelower portion of the disk; and an extension supported adjacent the seedtube lower end portion and extending forwardly thereof closely adjacentthe rearwardly directed disk surface, the extension being locatedsubstantially within the rear disk profile and adapted for preventingloose soil on the side of the furrow opposite the rearwardly directeddisk surface from entering the furrow in advance of material dischargedtherein through the seed tube outlet opening, the seed tube andextension being jointly mounted to the opener assembly for hingedmovement away from the disk to allow the passage of trash and debrisbetween the jointly mounted seed tube and extension and the disk. 22.The opener assembly according to claim 21 wherein the seed tube andextension are hingedly mounted to the opener assembly at a forwardlocation with respect to the rearwardly directed disk surface.
 23. Theopener assembly according to claim 22 wherein the seed tube andextension are jointly mounted for hinged movement about a hinge axisoriented at no more than a small acute angle to the vertical direction.